OPENSTAX MICROBIOLOGY CHAPTER
13,14,15,16 EXAMINATION TEST SOLVED
QUESTIONS AND FULL COURSE MATERIALS
UPDATED 2026.
◍ Static. Ans: Agent that inhibit growth of the microbe allowing the
immune system to catch up
◍ Decimal Reduction Time (DRT). Ans: the time, in minutes, in
which 90% of a population of bacteria at a given temperature will be
killed
◍ Methods of microbial control. Ans: physical and chemical
◍ Physical methods of microbial control. Ans: Exposure to extremes
of heat
Exposure to extremes of cold
Desiccation
Filtration
Osmotic pressure
Radiation
◍ Chemical Methods of Microbial Control. Ans: concentration of
disinfectant, organic matter, pH, time
, ◍ Fermentation microbial control. Ans: Process by which cells
release energy in the absence of oxygen
◍ osmotic pressure microbial control. Ans: uses high concentrations
of sugar and salt to inhibit microbial growth. removes water so
microbes cant function
◍ septicemia. Ans: growth of bacteria in the blood
◍ Low temperature microbial control. Ans: inhibits microbial
growth (refrigeration, deep freezing, lyophilization)
◍ High pressure microbial control. Ans: denatures proteins
◍ Radiation control. Ans: Irreversibly damage to DNA
◍ Sonication. Ans: the use of high frequency sound waves to break
open cells
◍ Filtration. Ans: A process that separates materials based on the
size of their particles. Hepa or membrane filter
◍ heavy metals. Ans: metallic elements with a high density that are
toxic to organisms at low concentrations
13,14,15,16 EXAMINATION TEST SOLVED
QUESTIONS AND FULL COURSE MATERIALS
UPDATED 2026.
◍ Static. Ans: Agent that inhibit growth of the microbe allowing the
immune system to catch up
◍ Decimal Reduction Time (DRT). Ans: the time, in minutes, in
which 90% of a population of bacteria at a given temperature will be
killed
◍ Methods of microbial control. Ans: physical and chemical
◍ Physical methods of microbial control. Ans: Exposure to extremes
of heat
Exposure to extremes of cold
Desiccation
Filtration
Osmotic pressure
Radiation
◍ Chemical Methods of Microbial Control. Ans: concentration of
disinfectant, organic matter, pH, time
, ◍ Fermentation microbial control. Ans: Process by which cells
release energy in the absence of oxygen
◍ osmotic pressure microbial control. Ans: uses high concentrations
of sugar and salt to inhibit microbial growth. removes water so
microbes cant function
◍ septicemia. Ans: growth of bacteria in the blood
◍ Low temperature microbial control. Ans: inhibits microbial
growth (refrigeration, deep freezing, lyophilization)
◍ High pressure microbial control. Ans: denatures proteins
◍ Radiation control. Ans: Irreversibly damage to DNA
◍ Sonication. Ans: the use of high frequency sound waves to break
open cells
◍ Filtration. Ans: A process that separates materials based on the
size of their particles. Hepa or membrane filter
◍ heavy metals. Ans: metallic elements with a high density that are
toxic to organisms at low concentrations
